QTabWidget::pane {
    border: 1px solid #cccccc;
    border-top: none;
    background: white;
}
QTabBar::tab {
    background-color: #f5f5f5;
    border: 1px solid #cccccc;
    border-bottom: none;
    padding: 6px 16px;
    margin-right: 2px;
}
QTabBar::tab:selected {
    background-color: white;
    border-bottom: 1px solid white;
    margin-bottom: -1px;
}
QTabBar::tab:hover:!selected {
    background-color: #ebebeb;
}
QTabBar::tab:first {
    margin-left: 0;
}